<!doctype html>
<html>
<head>
<!-- Global site tag (gtag.js) - Google Analytics -->
<script async src="https://www.googletagmanager.com/gtag/js?id=UA-114672259-1"></script>
<script>
  window.dataLayer = window.dataLayer || [];
  function gtag(){dataLayer.push(arguments);}
  gtag('js', new Date());
  gtag('config', 'UA-114672259-1');
  gtag('set', {'user_id': 'USER_ID'});
</script>
<meta charset='UTF-8'><meta name='viewport' content='width=device-width initial-scale=1'>
<title>三代测序专题☞测序技术简介.md</title><link href='http://fonts.googleapis.com/css?family=Open+Sans:400italic,700italic,700,400&subset=latin,latin-ext' rel='stylesheet' type='text/css'><style type='text/css'>html, body {overflow-x: initial !important;}html { font-size: 14px; background-color: rgb(255, 255, 255); color: rgb(51, 51, 51); }
body { margin: 0px; padding: 0px; height: auto; bottom: 0px; top: 0px; left: 0px; right: 0px; font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 1rem; line-height: 1.42857143; overflow-x: hidden; background-image: inherit; background-size: inherit; background-attachment: inherit; background-origin: inherit; background-clip: inherit; background-color: inherit; background-position: inherit inherit; background-repeat: inherit inherit; }
a:active, a:hover { outline: 0px; }
.in-text-selection, ::selection { background-color: rgb(181, 214, 252); text-shadow: none; background-position: initial initial; background-repeat: initial initial; }
#write { margin: 0px auto; height: auto; width: inherit; word-break: normal; word-wrap: break-word; position: relative; padding-bottom: 70px; white-space: pre-wrap; overflow-x: auto; }
.for-image #write { padding-left: 8px; padding-right: 8px; }
body.typora-export { padding-left: 30px; padding-right: 30px; }
@media screen and (max-width: 500px) { 
  body.typora-export { padding-left: 0px; padding-right: 0px; }
  .CodeMirror-sizer { margin-left: 0px !important; }
  .CodeMirror-gutters { display: none !important; }
}
.typora-export #write { margin: 0px auto; }
#write > p:first-child, #write > ul:first-child, #write > ol:first-child, #write > pre:first-child, #write > blockquote:first-child, #write > div:first-child, #write > table:first-child { margin-top: 30px; }
#write li > table:first-child { margin-top: -20px; }
img { max-width: 100%; vertical-align: middle; }
input, button, select, textarea { color: inherit; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-weight: inherit; line-height: inherit; }
input[type="checkbox"], input[type="radio"] { line-height: normal; padding: 0px; }
::before, ::after, * { box-sizing: border-box; }
#write p, #write h1, #write h2, #write h3, #write h4, #write h5, #write h6, #write div, #write pre { width: inherit; }
#write p, #write h1, #write h2, #write h3, #write h4, #write h5, #write h6 { position: relative; }
h1 { font-size: 2rem; }
h2 { font-size: 1.8rem; }
h3 { font-size: 1.6rem; }
h4 { font-size: 1.4rem; }
h5 { font-size: 1.2rem; }
h6 { font-size: 1rem; }
p { -webkit-margin-before: 1rem; -webkit-margin-after: 1rem; -webkit-margin-start: 0px; -webkit-margin-end: 0px; }
.mathjax-block { margin-top: 0px; margin-bottom: 0px; -webkit-margin-before: 0rem; -webkit-margin-after: 0rem; }
.hidden { display: none; }
.md-blockmeta { color: rgb(204, 204, 204); font-weight: bold; font-style: italic; }
a { cursor: pointer; }
#write input[type="checkbox"] { cursor: pointer; width: inherit; height: inherit; margin: 4px 0px 0px; }
tr { break-inside: avoid; break-after: auto; }
thead { display: table-header-group; }
table { border-collapse: collapse; border-spacing: 0px; width: 100%; overflow: auto; break-inside: auto; text-align: left; }
table.md-table td { min-width: 80px; }
.CodeMirror-gutters { border-right-width: 0px; background-color: inherit; }
.CodeMirror { text-align: left; }
.CodeMirror-placeholder { opacity: 0.3; }
.CodeMirror pre { padding: 0px 4px; }
.CodeMirror-lines { padding: 0px; }
div.hr:focus { cursor: none; }
pre { white-space: pre-wrap; }
.CodeMirror-gutters { margin-right: 4px; }
.md-fences { font-size: 0.9rem; display: block; break-inside: avoid; text-align: left; overflow: visible; white-space: pre; background-image: inherit; background-size: inherit; background-attachment: inherit; background-origin: inherit; background-clip: inherit; background-color: inherit; position: relative !important; background-position: inherit inherit; background-repeat: inherit inherit; }
.md-diagram-panel { width: 100%; margin-top: 10px; text-align: center; padding-top: 0px; padding-bottom: 8px; overflow-x: auto; }
.md-fences .CodeMirror.CodeMirror-wrap { top: -1.6em; margin-bottom: -1.6em; }
.md-fences.mock-cm { white-space: pre-wrap; }
.show-fences-line-number .md-fences { padding-left: 0px; }
.show-fences-line-number .md-fences.mock-cm { padding-left: 40px; }
.footnotes { opacity: 0.8; font-size: 0.9rem; padding-top: 1em; padding-bottom: 1em; }
.footnotes + .footnotes { margin-top: -1em; }
.md-reset { margin: 0px; padding: 0px; border: 0px; outline: 0px; vertical-align: top; background-color: transparent; text-decoration: none; text-shadow: none; float: none; position: static; width: auto; height: auto; white-space: nowrap; cursor: inherit; line-height: normal; font-weight: normal; text-align: left; box-sizing: content-box; direction: ltr; background-position: initial initial; background-repeat: initial initial; }
li div { padding-top: 0px; }
blockquote { margin: 1rem 0px; }
li p, li .mathjax-block { margin: 0.5rem 0px; }
li { margin: 0px; position: relative; }
blockquote > :last-child { margin-bottom: 0px; }
blockquote > :first-child { margin-top: 0px; }
.footnotes-area { color: rgb(136, 136, 136); margin-top: 0.714rem; padding-bottom: 0.143rem; }
@media print { 
  html, body { height: 100%; }
  .typora-export * { -webkit-print-color-adjust: exact; }
  h1, h2, h3, h4, h5, h6 { break-after: avoid-page; orphans: 2; }
  p { orphans: 4; }
  html.blink-to-pdf { font-size: 13px; }
  .typora-export #write { padding-left: 1cm; padding-right: 1cm; }
  .typora-export #write::after { height: 0px; }
  @page { margin: 20mm 0mm; }
}
.footnote-line { margin-top: 0.714em; font-size: 0.7em; }
a img, img a { cursor: pointer; }
pre.md-meta-block { font-size: 0.8rem; min-height: 2.86rem; white-space: pre-wrap; background-color: rgb(204, 204, 204); display: block; overflow-x: hidden; background-position: initial initial; background-repeat: initial initial; }
p .md-image:only-child { display: inline-block; width: 100%; text-align: center; }
#write .MathJax_Display { margin: 0.8em 0px 0px; }
.mathjax-block { white-space: pre; overflow: hidden; width: 100%; }
p + .mathjax-block { margin-top: -1.143rem; }
.mathjax-block:not(:empty)::after { display: none; }
[contenteditable="true"]:active, [contenteditable="true"]:focus { outline: none; box-shadow: none; }
.task-list { list-style-type: none; }
.task-list-item { position: relative; padding-left: 1em; }
.task-list-item input { position: absolute; top: 0px; left: 0px; }
.math { font-size: 1rem; }
.md-toc { min-height: 3.58rem; position: relative; font-size: 0.9rem; border-top-left-radius: 10px; border-top-right-radius: 10px; border-bottom-right-radius: 10px; border-bottom-left-radius: 10px; }
.md-toc-content { position: relative; margin-left: 0px; }
.md-toc::after, .md-toc-content::after { display: none; }
.md-toc-item { display: block; color: rgb(65, 131, 196); text-decoration: none; }
.md-toc-inner:hover { }
.md-toc-inner { display: inline-block; cursor: pointer; }
.md-toc-h1 .md-toc-inner { margin-left: 0px; font-weight: bold; }
.md-toc-h2 .md-toc-inner { margin-left: 2em; }
.md-toc-h3 .md-toc-inner { margin-left: 4em; }
.md-toc-h4 .md-toc-inner { margin-left: 6em; }
.md-toc-h5 .md-toc-inner { margin-left: 8em; }
.md-toc-h6 .md-toc-inner { margin-left: 10em; }
@media screen and (max-width: 48em) { 
  .md-toc-h3 .md-toc-inner { margin-left: 3.5em; }
  .md-toc-h4 .md-toc-inner { margin-left: 5em; }
  .md-toc-h5 .md-toc-inner { margin-left: 6.5em; }
  .md-toc-h6 .md-toc-inner { margin-left: 8em; }
}
a.md-toc-inner { font-size: inherit; font-style: inherit; font-weight: inherit; line-height: inherit; }
.footnote-line a:not(.reversefootnote) { color: inherit; }
.md-attr { display: none; }
.md-fn-count::after { content: '.'; }
.md-tag { opacity: 0.5; }
.md-comment { color: rgb(162, 127, 3); opacity: 0.8; font-family: monospace; }
code { text-align: left; }
h1 .md-tag, h2 .md-tag, h3 .md-tag, h4 .md-tag, h5 .md-tag, h6 .md-tag { font-weight: initial; opacity: 0.35; }
a.md-print-anchor { border: none !important; display: inline-block !important; position: absolute !important; width: 1px !important; right: 0px !important; outline: none !important; background-color: transparent !important; text-shadow: initial !important; background-position: initial initial !important; background-repeat: initial initial !important; }
.md-inline-math .MathJax_SVG .noError { display: none !important; }
.mathjax-block .MathJax_SVG_Display { text-align: center; margin: 1em 0em; position: relative; text-indent: 0px; max-width: none; max-height: none; min-height: 0px; min-width: 100%; width: auto; display: block !important; }
.MathJax_SVG_Display, .md-inline-math .MathJax_SVG_Display { width: auto; margin: inherit; display: inline-block !important; }
.MathJax_SVG .MJX-monospace { font-family: monospace; }
.MathJax_SVG .MJX-sans-serif { font-family: sans-serif; }
.MathJax_SVG { display: inline; font-style: normal; font-weight: normal; line-height: normal; zoom: 90%; text-indent: 0px; text-align: left; text-transform: none; letter-spacing: normal; word-spacing: normal; word-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; }
.MathJax_SVG * { transition: none; }


@include-when-export url(http://fonts.googleapis.com/css?family=Open+Sans:400italic,700italic,700,400&subset=latin,latin-ext);

/**
 * css forked from https://github.com/GitbookIO/gitbook 
 * www.gitbook.com
 * Apache License
 * https://github.com/GitbookIO/gitbook/blob/master/LICENSE
 **/

@font-face {
    font-family: 'Open Sans';
    font-style: normal;
    font-weight: normal;
    src: local('Open Sans Regular'),url('file:///Users/lx/Library/Application%20Support/abnerworks.Typora/themes/github/400.woff') format('woff')
}

@font-face {
    font-family: 'Open Sans';
    font-style: italic;
    font-weight: normal;
    src: local('Open Sans Italic'),url('file:///Users/lx/Library/Application%20Support/abnerworks.Typora/themes/github/400i.woff') format('woff')
}

@font-face {
    font-family: 'Open Sans';
    font-style: normal;
    font-weight: bold;
    src: local('Open Sans Bold'),url('file:///Users/lx/Library/Application%20Support/abnerworks.Typora/themes/github/700.woff') format('woff')
}

@font-face {
    font-family: 'Open Sans';
    font-style: italic;
    font-weight: bold;
    src: local('Open Sans Bold Italic'),url('file:///Users/lx/Library/Application%20Support/abnerworks.Typora/themes/github/700i.woff') format('woff')
}

html {
    font-size: 16px;
}

body {
    font-family: "Open Sans","Clear Sans","Helvetica Neue",Helvetica,Arial,sans-serif;
    color: rgb(51, 51, 51);
    line-height: 1.6;
}

#write{
    max-width: 860px;
  	margin: 0 auto;
  	padding: 20px 30px 40px 30px;
	padding-top: 20px;
    padding-bottom: 100px;
}
#write > ul:first-child,
#write > ol:first-child{
    margin-top: 30px;
}

body > *:first-child {
    margin-top: 0 !important;
}
body > *:last-child {
    margin-bottom: 0 !important;
}
a {
    color: #4183C4;
}
h1,
h2,
h3,
h4,
h5,
h6 {
    position: relative;
    margin-top: 1rem;
    margin-bottom: 1rem;
    font-weight: bold;
    line-height: 1.4;
    cursor: text;
}
h1:hover a.anchor,
h2:hover a.anchor,
h3:hover a.anchor,
h4:hover a.anchor,
h5:hover a.anchor,
h6:hover a.anchor {
    /*background: url("file:///Users/lx/Library/Application%20Support/images/modules/styleguide/para.png") no-repeat 10px center;*/
    text-decoration: none;
}
h1 tt,
h1 code {
    font-size: inherit;
}
h2 tt,
h2 code {
    font-size: inherit;
}
h3 tt,
h3 code {
    font-size: inherit;
}
h4 tt,
h4 code {
    font-size: inherit;
}
h5 tt,
h5 code {
    font-size: inherit;
}
h6 tt,
h6 code {
    font-size: inherit;
}
h1 {
    padding-bottom: .3em;
    font-size: 2.25em;
    line-height: 1.2;
    border-bottom: 1px solid #eee;
}
h2 {
   padding-bottom: .3em;
    font-size: 1.75em;
    line-height: 1.225;
    border-bottom: 1px solid #eee;
}
h3 {
    font-size: 1.5em;
    line-height: 1.43;
}
h4 {
    font-size: 1.25em;
}
h5 {
    font-size: 1em;
}
h6 {
   font-size: 1em;
    color: #777;
}
p,
blockquote,
ul,
ol,
dl,
table{
    margin: 0.8em 0;
}
li>ol,
li>ul {
    margin: 0 0;
}
hr {
    height: 4px;
    padding: 0;
    margin: 16px 0;
    background-color: #e7e7e7;
    border: 0 none;
    overflow: hidden;
    box-sizing: content-box;
    border-bottom: 1px solid #ddd;
}

body > h2:first-child {
    margin-top: 0;
    padding-top: 0;
}
body > h1:first-child {
    margin-top: 0;
    padding-top: 0;
}
body > h1:first-child + h2 {
    margin-top: 0;
    padding-top: 0;
}
body > h3:first-child,
body > h4:first-child,
body > h5:first-child,
body > h6:first-child {
    margin-top: 0;
    padding-top: 0;
}
a:first-child h1,
a:first-child h2,
a:first-child h3,
a:first-child h4,
a:first-child h5,
a:first-child h6 {
    margin-top: 0;
    padding-top: 0;
}
h1 p,
h2 p,
h3 p,
h4 p,
h5 p,
h6 p {
    margin-top: 0;
}
li p.first {
    display: inline-block;
}
ul,
ol {
    padding-left: 30px;
}
ul:first-child,
ol:first-child {
    margin-top: 0;
}
ul:last-child,
ol:last-child {
    margin-bottom: 0;
}
blockquote {
    border-left: 4px solid #dddddd;
    padding: 0 15px;
    color: #777777;
}
blockquote blockquote {
    padding-right: 0;
}
table {
    padding: 0;
    word-break: initial;
}
table tr {
    border-top: 1px solid #cccccc;
    background-color: white;
    margin: 0;
    padding: 0;
}
table tr:nth-child(2n) {
    background-color: #f8f8f8;
}
table tr th {
    font-weight: bold;
    border: 1px solid #cccccc;
    text-align: left;
    margin: 0;
    padding: 6px 13px;
}
table tr td {
    border: 1px solid #cccccc;
    text-align: left;
    margin: 0;
    padding: 6px 13px;
}
table tr th:first-child,
table tr td:first-child {
    margin-top: 0;
}
table tr th:last-child,
table tr td:last-child {
    margin-bottom: 0;
}

.CodeMirror-gutters {
    border-right: 1px solid #ddd;
}

.md-fences,
code,
tt {
    border: 1px solid #ddd;
    background-color: #f8f8f8;
    border-radius: 3px;
    padding: 0;
    font-family: Consolas, "Liberation Mono", Courier, monospace;
    padding: 2px 4px 0px 4px;
    font-size: 0.9em;
}

.md-fences {
    margin-bottom: 15px;
    margin-top: 15px;
    padding: 0.2em 1em;
    padding-top: 8px;
    padding-bottom: 6px;
}
.task-list{
	padding-left: 0;
}

.task-list-item {
	padding-left:32px;
}

.task-list-item input {
  top: 3px;
  left: 8px;
}

@media screen and (min-width: 914px) {
    /*body {
        width: 854px;
        margin: 0 auto;
    }*/
}
@media print {
    html {
        font-size: 13px;
    }
    table,
    pre {
        page-break-inside: avoid;
    }
    pre {
        word-wrap: break-word;
    }
}

.md-fences {
	background-color: #f8f8f8;
}
#write pre.md-meta-block {
	padding: 1rem;
    font-size: 85%;
    line-height: 1.45;
    background-color: #f7f7f7;
    border: 0;
    border-radius: 3px;
    color: #777777;
    margin-top: 0 !important;
}

.mathjax-block>.code-tooltip {
	bottom: .375rem;
}

#write>h3.md-focus:before{
	left: -1.5625rem;
	top: .375rem;
}
#write>h4.md-focus:before{
	left: -1.5625rem;
	top: .285714286rem;
}
#write>h5.md-focus:before{
	left: -1.5625rem;
	top: .285714286rem;
}
#write>h6.md-focus:before{
	left: -1.5625rem;
	top: .285714286rem;
}
.md-image>.md-meta {
    border: 1px solid #ddd;
    border-radius: 3px;
    font-family: Consolas, "Liberation Mono", Courier, monospace;
    padding: 2px 4px 0px 4px;
    font-size: 0.9em;
    color: inherit;
}

.md-tag{
	color: inherit;
}

.md-toc { 
    margin-top:20px;
    padding-bottom:20px;
}

#typora-quick-open {
    border: 1px solid #ddd;
    background-color: #f8f8f8;
}

#typora-quick-open-item {
    background-color: #FAFAFA;
    border-color: #FEFEFE #e5e5e5 #e5e5e5 #eee;
    border-style: solid;
    border-width: 1px;
}

#md-notification:before {
    top: 10px;
}

/** focus mode */
.on-focus-mode blockquote {
    border-left-color: rgba(85, 85, 85, 0.12);
}

header, .context-menu, .megamenu-content, footer{
    font-family: "Segoe UI", "Arial", sans-serif;
}


</style>
<script>
  (function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){
  (i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o),
  m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m)
  })(window,document,'script','https://www.google-analytics.com/analytics.js','ga');

  ga('create', 'UA-45156454-3', 'auto');
  ga('send', 'pageview');

</script>
</head>
<body class='typora-export' >
<div  id='write'  class = 'is-mac'><h1><a name='header-c364' class='md-header-anchor '></a>三代测序专题①测序技术简介</h1><p>❝</p><p>欧易购买的PacBio Sequel三代测序仪已于今年5月18日到货。借此东风，小编也开启了三代微信专题，为大家详细介绍三代测序的前世今生~</p><p>❞</p><hr /><p>自从1977年Fredrick Sanger等建立了双脱氧链终止法（Dideoxy Chain-Termination Method）测序技术以来，基因测序技术经历了几十年的快速发展，在此期间出现了两次技术上的飞跃：第一次飞跃是在Sanger测序技术（一代测序）实现自动化之后，科学家利用该技术完成了“人类基因组计划（Human Genome Project，HGP）”等重大科学研究项目；第二次飞跃是自2005年以来，以Roche 454、Illumina GA/HiSeq、Life SOLiD/Ion Torrent为代表的新一代测序技术（Next-Generation Sequencing，NGS）的出现，使得基因组测序通量快速增加，测序成本极大降低。近10年来，测序技术的发展速度已经远远超越了半导体信息技术进步的速度（摩尔定律，Moore’s Law），它将生命科学研究带入了基因组学时代。新一代测序技术已经在生命科学各个领域及农学、医学、环境保护、法医等领域中得到了广泛的应用。</p><h2><a name='header-c376' class='md-header-anchor '></a>一代测序</h2><p>第一代基因测序方法，即双脱氧链终止法，是由Fredrick Sanger等在1977年创立的（Sanger et al.，1977），因此，也被称为“Sanger测序法”。该方法是一种基于DNA聚合酶合成反应的测序技术。</p><p><img src='http://static.online.sciencereading.cn/readerpublic/afc7ae5a-9dfb-4133-3e5a-169e2f0e8cb2_d3b8ac6f6843e1d930ad6316733afcae/OPS/Images/Picture1_normal.png' alt='img' /></p><blockquote><p>图1 | 双脱氧链终止（Sanger）测序原理图（选自Sequencing forensic analysis and genetic analysis和Genes and genomics：a short course（3e），略有改动）</p></blockquote><p>Sanger测序法在出现之后的大约30年间，因其操作简便、测序读长长（为800 bp～1 kb）、数据准确性高，一直是应用最为广泛的DNA测序方法，甚至至今仍是验证新一代测序结果的金标准，常用于验证由新一代测序方法发现的新变异位点。尽管如此，其也存在相当大的局限性，如“测序偏好（Sequencing Bias）”、处理和分析等位基因频率的能力有限、通量太低、成本较高等。</p><h2><a name='header-c386' class='md-header-anchor '></a>二代测序</h2><p>第二代测序技术包括Roche 454公司的Genome Sequencer FLX测序平台，Illumina公司的Genome Analyzer、HiSeq系列、MiSeq、NextSeq500和MiniSeq等测序平台，Life公司的SOLiD测序系统、Ion Torrent Personal Genome Machine（PGM）、Proton等测序平台，Helicos Biosciences公司的Heliscope测序平台等许多种。第二代测序技术最显著的特点是通量高，单碱基测序成本低，一次测序运行可以对几十万至数亿条DNA模板进行测序。利用这些特点，人们可以方便地对各种生物物种进行全基因组深度测序、转录组测序、甲基化测序和ChIP测序等研究。</p><p>新一代测序技术通常又被称为大规模平行测序技术（Massively Parallel Sequencing，MPS），它可以同时完成测序模板互补链的合成与序列数据的读取。一般来说，二代测序包含下列连续的步骤：①向测序系统加入脱氧核苷酸；②检验和确定被加入的脱氧核苷酸类型；③去除测序反应的各种酶、荧光标记物或脱氧核苷酸的3′阻断基团等的洗脱反应；这样就实现了“边合成边测序（Sequencing By Synthesis，SBS）”，如454、Illumina、Ion Torrent等测序技术；或者“边连接边测序（Sequencing By Ligation，SBL）”，如SOLiD技术。</p><p><img src='http://static.online.sciencereading.cn/readerpublic/afc7ae5a-9dfb-4133-3e5a-169e2f0e8cb2_d3b8ac6f6843e1d930ad6316733afcae/OPS/Images/Picture2_normal.png' alt='img' /></p><blockquote><p>图2 | 454 GS FLX测序仪及测序原理图（选自Rothberg and Leamon，2008和Mardis，2008，略有改动）</p></blockquote><p><img src='http://static.online.sciencereading.cn/readerpublic/afc7ae5a-9dfb-4133-3e5a-169e2f0e8cb2_d3b8ac6f6843e1d930ad6316733afcae/OPS/Images/Picture3_normal.png' alt='img' /></p><blockquote><p>图3 | Illumina测序仪图片</p><p>A. Illumina GAII测序仪；B. HiSeq2500测序仪；C. MiSeq测序仪；D. NextSeq500测序仪；E. HiSeq4000测序仪；F. MiniSeq测序仪；G. HiSeq X-Ten测序仪</p></blockquote><p><img src='http://static.online.sciencereading.cn/readerpublic/afc7ae5a-9dfb-4133-3e5a-169e2f0e8cb2_d3b8ac6f6843e1d930ad6316733afcae/OPS/Images/Picture4_normal.png' alt='img' /></p><blockquote><p>图4 | Illumina测序技术原理（选自Mardis，2008，略有改动）</p></blockquote><p><img src='http://static.online.sciencereading.cn/readerpublic/afc7ae5a-9dfb-4133-3e5a-169e2f0e8cb2_d3b8ac6f6843e1d930ad6316733afcae/OPS/Images/Picture5_normal.png' alt='img' /></p><blockquote><p>图5 | SOLiD测序仪及测序原理图（选自Mardis，2008，略有改动）</p></blockquote><p><img src='http://static.online.sciencereading.cn/readerpublic/afc7ae5a-9dfb-4133-3e5a-169e2f0e8cb2_d3b8ac6f6843e1d930ad6316733afcae/OPS/Images/Picture6_normal.png' alt='img' /></p><blockquote><p>图6 | Ion Torrent测序仪及测序原理图（选自Rothberg et al.，2011，略有改动）</p></blockquote><h2><a name='header-c418' class='md-header-anchor '></a>三代测序</h2><p>有别于Illumina、SOLiD等第二代测序技术，PacBio Sequel、PacBio RS系列、Oxford Nanopore等测序平台因其实现了单分子实时测序，省去了第二代测序技术中的模板扩增步骤，所以被称为第三代测序。</p><p>Pacific BioSciences公司推出的单分子实时（Single Molecular Real Time，SMRT）DNA测序技术也是基于边合成边测序的原理。该技术主要特点是读长长，平均序列读长在10 kb以上，最长读长可达60 kb。</p><p><img src='https://ws4.sinaimg.cn/large/006tNc79gy1fgch6wcie2j31gi13d4qp.jpg' alt='' /></p><blockquote><p>图7 | PacBio测序仪及原理图</p><p>A.Sequel测序仪；B.RS II测序仪；C.ZMW；D.SMRT测序原理</p></blockquote><p>1996年，Kasianowicz等提出可以利用纳米孔（Nanopore）作为生物感应器，用于DNA和RNA测序（Kasianowicz et al.，1996），但因为技术上的限制，基于纳米孔的测序技术在近一两年才出现在测序市场上。针对不同通量需求的用户，Oxford Nanopore公司于2014年推出了几款基于纳米孔测序技术的测序仪，分别是MinION、PromethION和GridION（图8A，B，C）。</p><p><img src='http://static.online.sciencereading.cn/readerpublic/afc7ae5a-9dfb-4133-3e5a-169e2f0e8cb2_d3b8ac6f6843e1d930ad6316733afcae/OPS/Images/Picture8_normal.png' alt='img' /></p><blockquote><p>图8 | 纳米孔测序仪和测序原理图（选自Eid et al.，2009，略有改动）</p></blockquote><h2><a name='header-c430' class='md-header-anchor '></a>参考文献</h2><p>陈浩峰. 新一代基因组测序技术[M]. 科学出版社, 2016.</p><hr /><p>❝</p><p>今天小编先带大家回顾一下测序技术的发展，下期会为大家详细介绍PacBio Sequel系统所用三代测序技术。</p><p>❞</p></div>
</body>
</html>